Advocacy & Safety - Wind powered headlight.

Bike Forums friends,
This just in...


A group of students from Kaohsiung National First University of Science and Technology in southern Taiwan won an award Tuesday for creative application at the 2008 National Wind Power Invention Contest with their entry of a wind-powered bicycle headlight.

...The wind-powered bicycle headlight utilizes head-on wind, while the bike is in motion, to generate electricity as a source of energy for the headlight. The electricity is saved in rechargeable batteries and may be used to power a small fan when the cyclist stops at traffic lights.
http://www.etaiwannews.com/etn/news_content.php?id=762845

Whad'ya thinka THAT?

Hmm, could the batteries store wind power when I go downhill, and then help power me up the hill with the little fan? Thats what I need. Then, some cup holders. And A/C is nice. I suppose I would have to add two more wheels to carry the contraption around. But it would be nice. Maybe get a radio too.

jim

what the hell, why didn't someone think of this before? This is genius! And where are the pictures?! I want to see this light and how big the intake would have to be to power it.

Brilliant!

I saw this several months ago, I was thinking for sale, not sure if it's the same item or not.

Anyway, I think it's just a dumb idea. That "wind" is not free energy out there, that's coming from the effort you're putting into it, only in a less efficient way than using a direct drive. It's like having your air conditioner run by a separate little wheel that hangs out beside the car instead of directly off the motor.

Here it was: http://www.treehugger.com/files/2006/07/a_double_whammy.php

I saw this several months ago, I was thinking for sale, not sure if it's the same item or not.

Anyway, I think it's just a dumb idea. That "wind" is not free energy out there, that's coming from the effort you're putting into it, only in a less efficient way than using a direct drive. It's like having your air conditioner run by a separate little wheel that hangs out beside the car instead of directly off the motor.

Here it was: http://www.treehugger.com/files/2006/07/a_double_whammy.php

I wonder if it really is less efficient. It's positioned directly in front of your body so it's using air air resistance you would have to overcome anyway. An LED light would require very little energy and you wouldn't need wiring or special hubs or whatever. Plus it could charge itself on windy days while the bike is parked.

I wonder if it really is less efficient. It's positioned directly in front of your body so it's using air air resistance you would have to overcome anyway. An LED light would require very little energy and you wouldn't need wiring or special hubs or whatever. Plus it could charge itself on windy days while the bike is parked.

The fan isn't going to create a reasonable draft, you still have the fight the air when it hits your body anyway.

No free lunch.

Ok, for those not convinced this is not effecient, lets do a little thought experiement.

Suppose wind powered generator on a vehicle is really awesome, and someday in the future even Airplanes use this to power their lights.
Can you picture it? an airplane with a spinning windmill generator on the wingtip, using it to get power?
!But Wait! whats that spining propeller thing thats already on the airplane's nose pulling it forward???
Jee, maybe we would have been better off just putting a pulley between our little generator and that airplane's engine...then we won't have the extra weight and drag of the windmill blades!
Wait a sec! that what airplanes do already! they drive their generator off the motor power.

Just like what a hub generator in a bike does already.

I don't think it's silly at all. Any means of producing power is going to generate friction, and it looks like it'd be a snap to install compared to a hub generator (and therefore less expensive to install). Just stick it on the bars, rather than build an entire wheel.

I doubt I'd want one, but if it's made well it can be an excellent alternative to hub generators.

As noted, the efficiency of this will less than a generator hub, or bottle dynamo. Certainly it'd be easier to install than a hub (new wheel), but a bottle dynamo is just a simple.

The real problem is that the power produced will be a lot less than a dynamo for a given speed. Whenever someone comes out with a wind powered device, they are inevitably connected to a rechargeable battery, and then they neglect to mention that the batteries still have to be charged from another source. Maybe less often, but still.

As noted, the efficiency of this will less than a generator hub, or bottle dynamo.
How can you possibly know that, at this time? Keeping in mind that I am well aware that drag is the single most important factor in your cycling performance, there aren't any published specs on how much the device increases your drag coefficient.

It's kind of absurd to trash a product that has no specifications, no price tag, no manufacturer and no distributor, based on its potential performance.... ;)

this will rob rider energy like anything else

it takes more rider force to drive into a headwind with a fan, than driving into a headwind
without it

grab a pinwheel and stick it in a fan. is there any force pushing the plastic stick ?

[think really hard if you don't agree, and don't bother posting cuz you are wrong]


wind power light is a cool idea and will sell, even if it doesn't work so great. good for
commuters who want a tiny led blinkie and don't care about performance. it'll be no
good for the serious rider who trucks along and needs to conserve energy

Is there going to be a helmet mount? I guess you all know where I'm going with this.

Is there going to be a helmet mount? I guess you all know where I'm going with this.

Let me put on my thinking cap and ponder where you are going.

Ooh-Ohh, I know! A propeller helmet!

Efficiency/drag aside, i just can't see them getting any more than a watt out of it, making it all but useless except as a 'be seen' light and even then...

Maybe the best wind source is the one coming out the back side of the rider, especially after eating a big bean burrito. Now if there was a way to harness that power it would truly be a win-win situation. :D

Maybe Ford will get this brilliant idea as well. Then instead of having all those belts on your car engine, you'll just have windmills stuck all over the car to pump the oil, pump the coolant, run the AC, run the alternator, run the power steering, operate the power brakes, etc. Wonder why they haven't thought of this little plan?

The actual gizmo they're coming up with has potential to be neat, it's just headed in wrong direction. I'm not aware of a cheap bright LED-operated generator-powered bicycle light, and that's what we need, just not wind powered.

Maybe Ford will get this brilliant idea as well. Then instead of having all those belts on your car engine, you'll just have windmills stuck all over the car to pump the oil, pump the coolant, run the AC, run the alternator, run the power steering, operate the power brakes, etc. Wonder why they haven't thought of this little plan?

The actual gizmo they're coming up with has potential to be neat, it's just headed in wrong direction. I'm not aware of a cheap bright LED-operated generator-powered bicycle light, and that's what we need, just not wind powered.
Good points.

For dynamo lights, you can either increase the dynamo output (and suck that energy out of the rider), or decrease consumption (through more efficient lights). Option 2 is the course to pursue, obviously.

However, I would also note that battery technology probably has greater room for improvement. The more expensive headlights pack a lot more juice into a smaller package than standard batteries. And the prices will come down.

Dynamo will always be limited by the limits of efficient lighting. In the next 20 years, we will have very lightweight, inexpensive, bright headlights, probably powered by rechargeable packs, as the best and most convenient option.

How can you possibly know that, at this time? Keeping in mind that I am well aware that drag is the single most important factor in your cycling performance, there aren't any published specs on how much the device increases your drag coefficient.

It's kind of absurd to trash a product that has no specifications, no price tag, no manufacturer and no distributor, based on its potential performance.... ;)

Because generating power from wind is inherently less efficient than generating power from a direct drive.

And it's not absurd to trash an idea that purports to be otherwise.

Old airplanes with no electrical system on the engine sometimes had a small windmill hanging out in the slipstream to power the radios and instruments. Produced more drag than the belt or gear driven ones hooked to the engine. Why would it be any different on a bike?

Old airplanes with no electrical system on the engine sometimes had a small windmill hanging out in the slipstream to power the radios and instruments. Produced more drag than the belt or gear driven ones hooked to the engine. Why would it be any different on a bike?

It was inefficient then, it would be inefficient now, just people are all wind power happy, regardless of physics...

I mean come on, water car.

Won't work with a tail wind so it'd better have a sizeable battery. I doubt it can be as efficient as a good generator hub. Good idea though.

I met a guy who actually believed he had invented an automobile that would run on wind power - as in perpetual motion kind of thing. He reasoned that the wind from the car going forward would create the power to make the car go forward.

OK, we can forgive him for ignorance, but he confided that he had spent over $50,000 on parts that he had yet to assemble for a test model.

To humor him, I asked him what would happen if the car went downhill and gained so much speed from the additional wind that the car started to speed out of control. He had that one figured out - the car would have brakes. Ironically.... the last thing his design actually needs at this point is brakes...

http://homepage.ntlworld.com/mtat/images/mini.jpg

Old airplanes with no electrical system on the engine sometimes had a small windmill hanging out in the slipstream to power the radios and instruments. Produced more drag than the belt or gear driven ones hooked to the engine. Why would it be any different on a bike?

Good point. Actually, passenger jets still have these wind generators as a back-up in case the engines fail. There have been astounding cases of jets gliding for hundreds of miles with only the wind generator to provide electricity for communications.

The problem with using a wind generator as a primary electricity producer is that the energy drag created has to be overcome by the primary propultion force of the aircraft/vehicle. It is like driving with your brakes on.

Use traditional bottle-type generator light and you will understand when you feel the additional load on your pedals. Unfortunately, energy still isn't free.

Those bottle generators obviously aren't very aerodynamic. They must cause a certain amount of wind resistance that doesn't contribute to their function, so let's be sure to subtract that from the equation.